Recommendations for vias in pads for VNH2SP30

Support Motor controllers/drivers and motors
1

Hello,

I have a questions regarding the vias in pads for the Vcc, OUTa and OUTb thermal pads under the VNH2SP30 part. I am unable to find any thermal and PCB layout guides from the manufacturer and would like to know if you guys have any recommendations.

We are using the VNH2SP30 to drive a linear actuator, that can draw 4 - 7 Amps depending on the load, on a 4-layer 2oz copper PCB. We have plated vias in pads for the three thermal pads under the VNH2SP30, as you guys do in the Jrk 12v12 USB Motor Controller board. The three thermal pads are connected to their respective internal plane layer and top and bottom copper pour layer through these vias. Our board assembler is recommending that we remove the vias from the pads because they believe that it is pulling the solder away from the thermal pads and leading it to overheat.

Would it be a good idea to remove the vias from the three thermal pads and just place multiple vias around the pads?

Any feedback is greatly appreciated.

Thanks!

2

Hello.

If you really only need 4-7 amps, you probably don’t need to worry about this much. That said, vias in pads are pretty typical, though I suspect there are many ways to deal with it. We tent out vias (solder mask is covering the hole) on the side opposite from the pad, and we usually design our stencils to avoid paste on the vias.

- Jan